Increased apomixis expression concurrent with genetic and epigenetic variation in a newly synthesized Eragrostis
Diego C Zappacosta1, Ana C Ochogavía2, Juan M Rodrigo3
11] Departamento de Agronomía, Universidad Nacional del Sur, 8000 Bahía Blanca, Argentina [2] CERZOS-CONICET, CCT-Bahía Blanca, 8000 Bahía Blanca, Argentina.
Abstract:
Eragrostis curvula includes biotypes reproducing through obligate and facultative apomixis or, rarely, full sexuality. We previously generated a "tetraploid-dihaploid-tetraploid" series of plants consisting of a tetraploid apomictic plant (T), a sexual dihaploid plant (D) and a tetraploid artificial colchiploid (C). Initially, plant C was nearly 100% sexual. However, its capacity to form non-reduced embryo sacs dramatically increased over a four year period (2003-2007) to reach levels of 85-90%. Here, we confirmed high rates of apomixis in plant C, and used AFLPs and MSAPs to characterize the genetic and epigenetic variation observed in this plant in 2007 as compared to 2003. Of the polymorphic sequences, some had no coding potential whereas others were homologous to retrotransposons and/or protein-coding-like sequences. Our results suggest that in this particular plant system increased apomixis expression is concurrent with genetic and epigenetic modifications, possibly involving transposable elements.
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